The goal of RC1 is to demonstrate that the incidence of early childhood caries (ECC) in an American Indian (Al) reservation community can be reduced through the use of Motivational Interviewing (Ml) to change maternal oral health behaviors. The specific aims are: 1) to develop culturally relevant health education and promotional materials for use in ECC prevention with an Al community; 2) to manualize an oral health Ml intervention for pregnant women/mothers of newborns; and 3) to test this intervention in a randomized trial. All of the women, ages 15 or older, who are receiving prenatal care in the clinics of a large Northern Plains Al reservation, will be asked to participate in this trial, and all will be provided with the oral health promotion materials and aids, which will be developed using community participation strategies. For the demonstration trial, approximately 600 women will be randomly assigned to the Ml group, or the control condition. For those in the Ml group, oral health visits will be made to their homes prenatally and immediately after birth, then at 6, 12, 24, and 36 months of age. Children will be followed for 3 years, and caries assessments will be conducted by calibrated dental hygienists within 3 months of each child's 1st, 2nd, and 3rd birthday. The primary outcome will be annual increase in caries incidence. Secondary outcome measures will focus on caries patterns and cost-effectiveness of the program. A variety of mediators/moderators also will be examined, including such issues as mother's oral health knowledge and beliefs, stress, self-efficacy, and locus of control. AI/AN children have 3 times more untreated decay than children in the general population, and access to both preventive services and professional dental treatment are inadequate. The decision was made not to pair clinical/pharmacologic approaches with Ml in order to provide a definitive test of the most universally available strategy for prevention-thai is, home oral disease prevention behaviors. If the effectiveness of Ml for preventing ECC can be demonstrated, future studies might look at adaptations for community implementation. It is anticipated that lessons from this study can be used to adapt the final protocol for RC3, which is focused on the provision of oral health prevention services (including fluoride varnish) by specially trained Al community oral health specialists working in Head Start Centers. There are implications for use with other clinical approaches to prevention as well. A major strength of this study is the extent to which involvement by representatives of the participant community, as well as Al health service providers, is shaping the development of materials and the design of the research protocol. This participation is expected to be a major asset for dissemination activities as well.